Quantum Clock of Radioactive Decay
... a particle needs to traverse a barrier has remained controversial until now. In an attempt to address this issue, physicists gave rise to several concepts such as the phase, dwell, traversal and Larmor time. Peres and some others revived the concept of a quantum clock proposed by Salecker and Wigner ...
... a particle needs to traverse a barrier has remained controversial until now. In an attempt to address this issue, physicists gave rise to several concepts such as the phase, dwell, traversal and Larmor time. Peres and some others revived the concept of a quantum clock proposed by Salecker and Wigner ...
Slide 1
... oracle separation between QMA and QCMA. Our result: Arthur can verify xH using (1) a polynomial-size classical witness from Merlin, and (2) polynomially many quantum queries to the group oracle (but possibly an exponential amount of computation) ...
... oracle separation between QMA and QCMA. Our result: Arthur can verify xH using (1) a polynomial-size classical witness from Merlin, and (2) polynomially many quantum queries to the group oracle (but possibly an exponential amount of computation) ...
Bits and Qubits
... Umesh Vazirani (UC Berkeley) [link] – basics and beyond John Preskill (Caltech) [link] – basics and beyond Andrew Childs (U of Maryland) [link] – quantum algorithms John Watrous (U of Waterloo) [link] – quantum information ...
... Umesh Vazirani (UC Berkeley) [link] – basics and beyond John Preskill (Caltech) [link] – basics and beyond Andrew Childs (U of Maryland) [link] – quantum algorithms John Watrous (U of Waterloo) [link] – quantum information ...
Hidden Variables as Fruitful Dead Ends
... I’ve never understood how such people could be right, unless Nature were describable by a “classical polynomial-time hidden variable theory” (some of the skeptics admit this, others don’t) Well-known problem: It’s incredibly hard to construct such a theory that doesn’t contradict QM on existing expe ...
... I’ve never understood how such people could be right, unless Nature were describable by a “classical polynomial-time hidden variable theory” (some of the skeptics admit this, others don’t) Well-known problem: It’s incredibly hard to construct such a theory that doesn’t contradict QM on existing expe ...
Cryptography.ppt - 123SeminarsOnly.com
... The thing about photons is that once they're polarized, they can't be accurately measured again, except by a filter like the one that initially produced their current spin. So if a photon with a vertical spin is measured through a diagonal filter, either the photon won't pass through the filter or t ...
... The thing about photons is that once they're polarized, they can't be accurately measured again, except by a filter like the one that initially produced their current spin. So if a photon with a vertical spin is measured through a diagonal filter, either the photon won't pass through the filter or t ...
quantum paradox - Brian Whitworth
... ways that should cancel, like opposite spin. In sum, the quantum world described by quantum theory cannot possibly be physical. For example, an electron’s quantum wave can spread across a galaxy, then instantly collapse to any point when observed, but: “How can something real disappear instantaneous ...
... ways that should cancel, like opposite spin. In sum, the quantum world described by quantum theory cannot possibly be physical. For example, an electron’s quantum wave can spread across a galaxy, then instantly collapse to any point when observed, but: “How can something real disappear instantaneous ...
G020271-00
... Limit to TM position (strain) sensitivity for that optimal power for a given Tifo and frequency Minimize total quantum noise (quadrature sum of SN and RPN) for a given frequency and power ...
... Limit to TM position (strain) sensitivity for that optimal power for a given Tifo and frequency Minimize total quantum noise (quadrature sum of SN and RPN) for a given frequency and power ...
simulate quantum systems
... systems hinges on the exponential growth of the size of Hilbert space with the number of particles in the system. Keeping track of all degrees of freedom is thus a computationally expensive problem (e.g., the dimension of the Hilbert space of 20 qubits is > 106 ). As a result, classical computers ca ...
... systems hinges on the exponential growth of the size of Hilbert space with the number of particles in the system. Keeping track of all degrees of freedom is thus a computationally expensive problem (e.g., the dimension of the Hilbert space of 20 qubits is > 106 ). As a result, classical computers ca ...
Minimal separable quantizations of Stäckel systems
... ure ! g = jdet gj dx) complex functions on Q is called a minimal quantization of the Hamiltonian (1) in the metric g (that also de…nes the operators ri of the asociated Levi-Civita connection). In the standard approach to the quantization of (1) one assumes that g = A 1 (as it has been done in the c ...
... ure ! g = jdet gj dx) complex functions on Q is called a minimal quantization of the Hamiltonian (1) in the metric g (that also de…nes the operators ri of the asociated Levi-Civita connection). In the standard approach to the quantization of (1) one assumes that g = A 1 (as it has been done in the c ...
Quantum key distribution
Quantum key distribution (QKD) uses quantum mechanics to guarantee secure communication. It enables two parties to produce a shared random secret key known only to them, which can then be used to encrypt and decrypt messages. It is often incorrectly called quantum cryptography, as it is the most well known example of the group of quantum cryptographic tasks.An important and unique property of quantum key distribution is the ability of the two communicating users to detect the presence of any third party trying to gain knowledge of the key. This results from a fundamental aspect of quantum mechanics: the process of measuring a quantum system in general disturbs the system. A third party trying to eavesdrop on the key must in some way measure it, thus introducing detectable anomalies. By using quantum superpositions or quantum entanglement and transmitting information in quantum states, a communication system can be implemented which detects eavesdropping. If the level of eavesdropping is below a certain threshold, a key can be produced that is guaranteed to be secure (i.e. the eavesdropper has no information about it), otherwise no secure key is possible and communication is aborted.The security of encryption that uses quantum key distribution relies on the foundations of quantum mechanics, in contrast to traditional public key cryptography which relies on the computational difficulty of certain mathematical functions, and cannot provide any indication of eavesdropping at any point in the communication process, or any mathematical proof as to the actual complexity of reversing the one-way functions used. QKD has provable security based on information theory, and forward secrecy.Quantum key distribution is only used to produce and distribute a key, not to transmit any message data. This key can then be used with any chosen encryption algorithm to encrypt (and decrypt) a message, which can then be transmitted over a standard communication channel. The algorithm most commonly associated with QKD is the one-time pad, as it is provably secure when used with a secret, random key. In real world situations, it is often also used with encryption using symmetric key algorithms like the Advanced Encryption Standard algorithm. In the case of QKD this comparison is based on the assumption of perfect single-photon sources and detectors, that cannot be easily implemented.